Automatic analyzing device

ABSTRACT

An analyzing device which automatically and sequentially analyzes a large number and variety of chemical samples wherein the system operates with the sample, reagent, and cleaning solution flow lines pressurized with an inert gas, whereby the formation of air bubbles in the flow system, oxidation of samples and reagents and the rise of noxious fumes are prevented.

United States Patent [191 Naono May 6, 1975 AUTOMATIC ANALYZING DEVICE [56] References Cited [75] Inventor: Toyohiko Naono,Akishima, UNITED STATES PATENTS TokyoJapan 3230,048 1/1966 Skeggs 23/253 R [73] Assignee; Nihon nenshi Kabushiki K i h 3,557,077 l/l97l Brundfeldt et al..... 23/259 X Tokyo, Japan 3,666,420 5/1972 Paatzsch 23/253 R [22] Filed: 1973 Primary Examiner-R. E. Serwin [21] App]. No: 387,965 Attorney, Agent, or FirmWebb, Burden, Robinson &

Webb [30] Foreign Application Priority Data Aug. 15, l972 Japan 47-8l708 [57] ABSTRACT jfapan 47'8l715 An analyzing device which automatically and sequen- 1972 478l721 tially analyzes a large number and variety of chemical samples wherein the system operates with the sample, [52] Cl 23/253 23/259 5 g reagent, and cleaning solution flow lines pressurized 51 I t Cl G with an inert gas, whereby the formation of air bub- EE bles in the flow system, oxidation of samples and rea. 1 0 l R gents and the rise of noxious fumes are prevented.

6 Claims, 6 Drawing Figures PATENTEDNAY EIBTS SHEET 1 BF 4 h x453 ME 3:

NQKUMEQ AUTOMATIC ANALYZING DEVICE This invention relates to an automatic chemical analyzer suitable for use in medical laboratories, clinics, pharmacies and the like.

In the field of chemical and medical analysis, there has been a growing need to develop an apparatus which automatically and sequentially analyzes a large number and variety of chemical samples such as serums with high accuracy and reproducibility.

However, it has been very difficult to design an apparatus having fully automatic capabilities due to the m herent complicated nature of the operational system involved. In spite of such difficulties, however, it is highly desirable to provide a fully integrated system of automation covering such operations as sequential sampling, reagent selection, test type selection, reagent tube selection, flow line washing, etc.; otherwise, sequential analysis without crss-contamination of the solutions involved becomes impossible.

According to this invention there is provided an improved apparatus for automatically and sequentially analyzing a series of liquid samples, the samples being fractionally divided and diluted by a suitable diluent or reagent and analyzed by an instrument such as a colorimeter or flame photometer after the diluted samples have undergone chemical reaction under specific conditions.

It is an advantage of the automatic analyzer of this invention to provide for cleaning the reaction tubes and detection flow lines using different cleaning solutions.

Another advantage of this invention is to provide a novel means for cleaning the sampling system of the automatic analyzer.

A further advantage of this invention is to provide a unique valve through which treated liquid samples and cleaning solutions are periodically and sequentially passed.

Briefly, according to this invention, a sequential multitest system operates under pressurized closed flow conditions; that is to say, the sample, reagent and cleaning solution flow lines are pressurized with a gas such as nitrogen and thus isolated from the atmosphere. The advantages of this system are as follows: a) Since the flow lines are under pressure, no air bubbles form in the flow system. b) Samples and reagents are I not oxidized as they are not exposed to the atmosphere.

c) No corrosive or noxious fumes arise. d) The analytical mechanisms may be comparatively simple and durable.

The sequential multi-test system according to this invention permits automatic sequential analysis of multiconstituents in a single channel. With this system, analysis is carried out while automatically changing reagents in sequence. Each time a sample is analyzed, the flow line is cleaned and dried automatically before proceeding with the analysis of the next sample. All operations including data recording are carried out automatically by tape control techniques.

These and other objects of the invention will become apparent by reading the following detailed description in conjunction with the accompanying drawings, of which,

FIG. 1 is a diagrammatic illustration of the apparatus constituting the invention.

FIG. 2 is a partial cross-section of the sample measuring valve in accordance with this invention.

FIG. 3 shows the main parts constituting the sample measuring valve as shown in FIG. 2.

FIG. 4 is a diagrammatic illustration of the system for cleaning the sample measuring valve.

FIG. 5 shows the main parts constituting the reaction vessel selector valve.

FIG. 6 is a partial cross-section and partial break away view of the reaction bath.

THE OVERALL SYSTEM Referring now to FIG. 1, there is provided a reaction tube bath 1 in which ten reaction tubes 2-11 are contained. The reaction tube bath 1 in which the reaction tubes are housed is divided into two chambers 10] and 102 by sealed plate 100. Upper chamber I01 into which the reaction tubes open is filled with compressed nitrogen or another suitable gas supplied from a gas cylinder (not shown) via regulating valve 103, pressure gauge I04 and pipe 105. The upper chamber 101 is preferably maintained at a pressure of 1.5 3.0 kg/cm The lower chamber of the reaction tube bath 102 contains water, the temperature of which is thermostatically controlled by warm water piped through pipe 108 from water supply unit 107.

Liquid samples are automatically and sequentially fed into the reaction tubes 2-11 by a reaction tube selection valve 33 so that up to ten samples, representing for example, as many patients can be treated in a single measuring sequence.

A sampler comprises a turntable 12 (actually two turntables each accomodating forty samples) arranged to hold and position sample holding tubes 13 beneath a pipette I4. A sample is drawn from a holding tube 13 up through pipette 14 by a constant flow pump 15 and transferred to one of the sample measuring holes provided in a rotatable member 17 forming a part of the sample measuring valve 16. Constant sample volume is assured as the measuring holes are precisely machined and are all identical in size. Once the sample is in the sample measuring hole, rotary slide member I7 rotates by one tenth of a turn to align with flow line 32 through which a reagent from a reagent reservoir flows, thereby diluting the sample. The diluted sample is then delivered to the first reaction tube 2 via reaction tube selection valve 33. The turntable 12 automatically rotates 9 (360/) so that the next sample is positioned below pipette 14. The sampling and diluting procedure is repeated and the next sample is deposited in the next reaction tube. In this way, up to ten samples are sequentially transferred from the sample holding tubes to reaction tubes.

The reaction tube selection valve 33 acts as a selector ensuring that the first sample enters reaction tube 2, the second sample enters reaction tube 3, etc. through conduits shown only for reaction tubes 2 and 3 in FIG. 1. In other words, valve 33 and sample measuring valve 16 are synchronized and joined by a conduit 34. The valve has ten outlets 3544 (not all individually numbered in FIG. 1) each in communication with a different reaction tube.

Various reagents for example, water, acetic acid, etc. are held in reagent reservoirs -50 contained in a pressurized reagent box 31. A gas cylinder 51 containing an inert gas, such as nitrogen or argon, pressurizes the reagent reservoirs and thereby prevents the generation of air bubbles which would impair measurement accuracy. A valve 52 regulates the gas pressure. 53 is 3 a pressure gauge. The reservoirs are pressurized at about 1.5 3.0 kglcm Reagent selection valves 54-59 (only 54 and 59 are shown in FIG. 1) are provided with ten inlets a1-a10. Each outlet valve 54-59 has one numbered 60-65 respectively. Inlets a1-a10 (not all individually numbered in FIG. 1) of reagent selection valves 54-59 are connected by pipes (not all shown) to reagent reservoirs 45-50 respectively, while outlets 60-65 of the said respective reagent selection valves 54-59 are connected to the inlet side of the constant flow pumps 66-71 respectively (not all shown in FIG. 1). These pumps are controlled by an operation tape control system or the like so that the volume of reagent to be supplied to the reaction tubes is increased or decreased according to requirements by changing the number of pump strokes. The outlets of constant flow pumps 66-71 are connected to inlets 78-83 of reaction tube selector valve 72-77 respectively (not all shown). Outlets bl-bl of the said valves 72-77 are connected through pipes (not all shown) to the respective reaction tubes 2-11. These valves may be controlled, for example, by signals optically read from the operation tape.

Reagent valve 84 forming part of flow line 32 selects the reagent to be supplied to the sample measuring valve 16 supplied by conduit 85. The selected reagent is drawn through the sample by constant flow suction pump 86.

The sample reagent or reagents transferred to the reaction tubes are mixed by motor-driven stirrers 90-99 (not all shown) for a suitable period, according to the reaction time, prior to being analyzed.

Reaction tubes 2-11 are connected to reaction tube exhaust flush control valves (hereafter flush valves) 121-130 (only valves 121 and 130 are shown in FIG. 1) via pipes 109-118 (not all shown respectively. The flush valves are provided with ports cl-c7. A rotary slide in said valve is provided with a passageway 131, through which cleaning solutions may be applied to any one of the ports through outlet 133. The rotary slide in said valve is also provided with duct 132, which is joined to the reaction tube and may communicate with one of the ports. As shown in FIG. 1, outlet 133 and duct 132 always communicate with adjacent ports. Hence, when duct 132 coincides with port c1, the sample is forced out of reaction tube 2 by the force of the compressed gas in pressurized chamber 101 along pipe 109, through duct 132, along pipe 134, and through inlet d1 of valve 135, prior to entering analyzing instrument (detector) 137 where the sample is analyzed and an instrument reading converted into an electrical signal which is finally recorded by recorder 140. The detector may be a colorimeter, for example.

Subsequent samples contained in the remaining reaction tubes 3-11 are analyzed and recorded in the same way via valves 122-130 (not all shown in FIG. 1) and inlets d2-d10 of valve 135, respectively, detector 137 and recorder 140. A drain valve 139 drains off the sample after the sample has passed through the analyzing instrument (detector). A buffer tube 138 counteracts the flow-through pressure of the sample so as to position it exactly in the detector cell.

THE CLEANING SYSTEM The supply source of the cleaning system is contained in three reservoirs 151, 152, and 153 which are contained in a pressurized container 150. Reservoir 151 contains acidic or alkaline cleaning solution, reservoir 152 contains tap water and reservoir 153 contains distilled water.

The cleaning solution of reservoir 151 is drawn up by associated suction pump 163 through pipe 154 and into inlets c2 of flush valves 121-130. Also, part of the cleaning solution in this flow line is channelled through branch pipe 154a and enters circular passageway 131 of flush valves 121-130 via first rinse valve 155, second rinse valve 156 and pipe 157.

The tap water in reservoir 152 is similarly drawn up by a second suction pump 164 through pipe 158 and into inlets c4 of flush valves 121-130.

Finally, the distilled water in reservoir 153 is pumped through its designated flow line by associated pump 165 and bifuricated through pipe 159 so as to feed the liquid into inlets c6 of flush valves 121-130, the remaining portion passing through first rinse valve 155, second rinse valve 156 and pipe 157 and so into circular passageways 131 of the valves 121-130.

The outlets c3, c5, and c7 of flush valves 121-130 are joined to exhaust pipe 160, one end of which is exposed to the atmosphere.

First rinse valve is provided with inlets e1 e6 and outlet 162. Outlet 162 is in communication with the inlet of second rinse valve. when the outlet 162 is positioned at f1 and f2, cleaning of the reaction tubes and detection flow line is halted. A compressed inert gas of 1.5 3.0 kg/cm is supplied to inlets e3 and e6 from a gas tank (not shown) through valve 167 and pressure gauge 168 and conduit 161.

Outlets g1 610 (not all numbered in FIG. 1) of second rinse valve 156 are connected to circular passageway 131 of flush valves 121-130, respectively.

With this arrangement, the reaction tubes and the detection flow line can be washed with different cleaning solutions. When duct 132 of a flush valve 121 is moved from 01 (the sample delivery position) to c2 position by the intermittent rotation of one eighth of a turn of the rotary slide of flush valve 121, reaction tube 2 is cleaned with the first cleaning solution. The cleaning solution of the first reservoir 151 is drawn up by constant flow pump 163, transmitted to inlet c2 of flush valve 121 and then fed to reaction tube 2 through duct 132 thereby cleans reaction tube 2. A part of the cleaning solution flows over from the top of reaction tube 2 and flows to waste reservoir 106 through pipe 166. At this time, the duct 133 is connected to outlet 01 (see FIG. 3) and hence, the detection flow line is cleaned with cleaning solution also. To accomplish this, outlet 162 of first rinse valve 155 is positioned at inlet e1 or e4. The first cleaning solution is supplied to circular passageway 131 through rinse valves 155 and 156 and flows through the detection flow line after passing through outlet c1.

First rinse selection valve 155 is in turn rotated only one eighth of a turn in order to change the first cleaning solution to the third cleaning solution. Outlet 162 connects with inlet e2. Next, the third cleaning solution drawn up by pump is transferred to circular passageway 131 through valves 155 and 156 and then fed to the detection line so as to clean the analytical instrument (detector) 137. First rinse valve 155 is further rotated one eighth of a turn; outlet 162 thereby joins inlet e3 to which nitrogen gas is supplied from the gas tank (not shown). Then the residual solution in the detection line is blown off with pressurized nitrogen gas in order to dry the detection line. As a consequence, the detection line and detector are cleaned and thus do not contaminate the succeeding sample to be tested by analytical instrument (detector) 137.

After the detection line has been cleaned, outlet 162 of first rinse valve 155 is closed at the f2 position until the next sample (in reaction tube 3) is analyzed by the detector. Flush valve 121 is not rotated until outlet 162 of first rinse valve 155 next moves to the f2 position. With first rinse valve 155 under the above condition, flush valve 121 is rotated one eighth of a turn and then duct 132 and duct 133 are connected to outlets c3 and inlet c2, respectively. Thus, the first cleaning solution in reaction tube 2 passes through duct 132, then pipe 109 and is finally flushed from waste pipe 160.

Flush valve 121 is further rotated one eighth of a turn and duct 132 and duct 133 move to the c4 and c3 positions, respectively. The second cleaning solution drawn up by pump 164 in the second cleaning solution reservoir 152 is fed to reaction tube 2 through duct 132, thus the tube is cleaned. Flush valve 121 is then rotated one eighth of a turn after tube 2 has been cleaned by the second cleaning solution and then the second cleaning solution is flushed through outlet 05 and waste pipe 160.

Finally the third cleaning solution is transferred to the reaction tube 2 through inlet 06 of flush valve 121 and duct 132 and after that it is flushed from waste pipe 160 through outlet 07 in accordance with the rotation of flush valve 121.

Thus, the reaction tube is satisfactorily washed with three kinds of cleaning solutions after completion of each analysis, and finally, the residual solution is blown off with pressurized nitrogen gas supplied to chamber 101 to dry the reaction tube.

All of these operations may be automatically carried out by the operation tape. Furthermore, with this invention it is possible to wash two empty reaction tubes with cleaning solutions at the same time the samples are being analyzed.

REACTION BATH CONTROL The reaction tube bath 1 already described has associated therewith a drainage reservoir 106 which is closed and pressurized at 1.5 3.0 kg/cm with nitrogen gas supplied from the gas tank (not shown) through branch pipe 105a. This reservoir is equipped with two level gauges 170, which are used to detect the upper and lower levels of the drainage in order to keep the pressure drainage reservoir 106 constant. Level gauges 170 are connected to level detector 171 which operates drain valve 173 after receiving a signal from level gauges 170. When the cleaning solution is fed from pressurized chamber 101 to drainage reservoir 106, the drainage level goes up and upper level gauge 170 detects it; the level detector 171 operates so as to open valve 173. By opening valve 173, some of the drainage is flushed from valve 173 through drainage pipe 172 since the drainage is pressurized. Thus, the pressure in drainage reservoir 106 drops. In order to minimize fiuctuations in pressure, the level gauges are placed close to each other.

As is explained hereinabove, the system according to this invention allows automatic sequential analysis of multiconstituents by means of a single channel. With this system analysis is carried out while automatically changing reagents in sequence. Each time a sample is analyzed, the flow line is cleaned and dried automatically, and then analysis proceeds to the next sample.

VALVE ASSEMBLY FIG. 2 shows a cross-section of the novel sample measuring valve 16 used in FIG. 1. The same numerals used in each drawing indicate the same elements.

Rotatable slide 17 is arranged axially between the upper and lower fixed member 18 and 19 so as to contact each of them. These members are made of polytetrafluoroethylene resin, borosilicate glass, or ruby, whereby the said members are resistant to corrosion by reagents and solvents. Upper fixed member 18 is supported by a cylindrical casing positioned thereabout having conical hole 181 on its upper surface near the axis in which steel ball 182 is positioned. Casing 183 is threaded on to upper base plate 184 in order to bias the said steel ball 182 by means of rod 185 against casing 180. Spring 186 urges the said rod 185 against ball 182. Casing 180 is secured to plate 184 by screw 187 to prevent rotating thereof. Fitting 188 is secured to casing 180 and is used to make the pipe connection with the passageway of upper member 18. Lower fixed member 19 is supported by cylindrical casing 189 and 190 which are secured to lower base plate 191 by means of screws 192.

A cylindrical casing is provided to support rotatable slide member 17. Bushings 194 and 195 made of a material resistant to such corroding reagents and solvents are disposed between casing 180 and casing 193 and between casing 189 and casing 193 so as to provide a smooth rotation of member 17. Cylinder 193 is fixed to a Geneva gear 196 which is in working contact with roller 197. Shaft 198 which is secured to base plates 184 and 191 is provided with bevel gear 199 and arm 200 that supports the said roller 197. The said bevel gear 199 is meshed with bevel gear 201 which is secured to shaft 202 of motor 203. By driving motor 203, Geneva gear 196 is intermittently rotated through gears 201 and 199 and roller 197, thus, passageway 20 provided in a rotatable member 17 is positioned. Motor 203 is intermittently activated by a limit switch.

SAMPLE MEASURING VALVE ln P16. 3 rotary members and fixed members used in sample measuring valve 16 are shown. They would be supported by a suitable valve assembly explained with reference to FIG. 2. Rotatable member 17 has ten measuring holes 211-220 which are provided along the periphery thereof. These holes are accurately fabricated so that their volumes are the same. Upper fixed member 18 has two passageways 221 and 222, which are joined to constant flow pumps 86 and 15, respectively (see FIG. 1). Lower fixed member 19 is provided with passageways 223 and 224, the former being connected to reaction tube selection valve 33 and the latter to pipette 14 (see FIG. 1). The liquid sample to be analyzed is introduced into one of the measuring holes, for example, hole 218, through passageway 224. After the liquid sample is measured by the measuring hole, rotatable member 17 is rotated one tenth of a turn in the direction of the arrow and measuring hole 218 is is connected to passageways 221 and 223. Then the reagent supplied from the reagent tank is fed to passageway 221 so as to transmit the measured sample to the reaction tube through outlet 223.

At the same time, the next sample measuring hole 217 is washed as explained hereafter, by the cleaning solution which is fed from the cleaning solution tank to passageway 222; thereafter. the sample is measured by measuring hole 217.

CLEANING SYSTEM FOR MEASURING VALVE FIG. 4 schematically illustrates the cleaning system of the sample measuring valve. In order to wash, sample measuring valve 16 and pipette 14, three kinds of cleaning solutions are provided, each of which is drawn up in sequence by constant flow pump 15. One end of pump is connected to needle valve 233 comprising block 234 and plungers 235-238. Plungers 236-238 are connected to closed vessels 239, 240 and 241 through pipes 242, 243, and 244 respectively. These pressured vessels are pressurized with nitrogen gas. The first cleaning solution such as acid solution in the first tank 245 is drawn up and transmitted to vessel 239 by pump 246. Water is transferred from the second tank 247 into closed vessel 240 by pump 248. Also, distilled water in the third tank 249 is fed to vessel 241, by pump 250. Constant pressure valves 251, 252, and 253 are utilized so that when the pressure in the closed vessels becomes higher than the preset value, the valves are opened. Then the cleaning solution in the closed vessel is fed back to the cleaning solution tank.

Pressure gauges 254, 255 and 256 indicate the pressure of closed vessels 239, 240 and 241.

With this arrangement, when plunger 236 moves downward, pipes 242 and 257 come on line, and the cleaning solution in closed vessel 239 which is being pressurized with nitrogen gas, is transferred into needle valve 233 and in turn delivered to cleaning bath 231 after passing through sample measuring valve 16 and pipette 14. The second cleaning solution reserved in closed vessel 240, then is flushed through sample measuring valve 16 and pipette 14 to clean them after plunger 236 moves upward and plunger 237 downward.

Furthermore, in the same manner as the first and second cleaning solutions, the third cleaning solution in closed vessel 241 is used for cleaning valve 16 and pipette 14.

Thus, the sampling system including measuring valve 16 and pipette 14 is satisfactorily washed with three kinds of solutions to avoid cross-contamination. Cleaning is carried out after the sample is measured by sample measuring valve 16 and then transferred to the reaction tube. After termination of cleaning, pipette 14 is moved to the position indicated by the dotted lines and plunger 235 and pump 15 are operated so as to pick up the next sample to be analyzed for measurement by sample measuring valve 16. After that, constant flow pump 15 is stopped and the sample measuring valve 16 is rotated one tenth of a turn; thus, the measured sample is supplied to the reaction tube with reagent transferred from reagent box 31 (see FIG. 1) into valve 16 through pipe 32. All these operations may be carried out automatically by the operation control tape.

FLUSH VALVE FIG. 5 shows a perspective view of the main components of valve 121 in FIG. 1, in which rotary slide 261, and upper and lower fixed members 262 and 263 are illustrated. These components which are made of polytetrafluoroethylene resin or ruby are arranged in the valve assembly in the same manner as explained with reference in FIG. 2. Rotary slide26l is provided with duct 133 and slanted duct 132 which is radially spaced from hole 133 one eighth of a turn therefrom. Upper fixed member 262 is provided with circular passageway 131 on one surface thereof and ducts 109 and 157. One end of duct 109 is extended to the center of the surface of member 262 and is joined to the end of slanted duct 132 of rotary slide 261; the other end of passageway 109 is connected to reaction tube 2. One end of duct 157 is connected to valve 156 and the other end is connected to circular passageway 131. Outlet ports c1 c7 are provided in the lower member radially spaced along the periphery thereof, but at one position, 08, no port is provided. By contacting rotary slide 261 with the upper and lower member 262 and 263, duct 133 is connected to circular passageway 131 and one of the ports, for example (7; duct 132 is connected to duct 109 and one of the ports, for example, c6. When the slanted duct 132 is at the c8 (closed) position, the sample is treated in the reaction tube 2.

REACTION BATH FIG. 6 shows a partial cross-section of the reaction bath utilized for reaction of the sample to be analyzed. Reaction tube 2 whose upper end is open and lower end is conically shaped, is installed in reaction bath 1. The reaction bath is basically formed by plates 27], 272, 273 and 274 defining an enclosure divided into two compartments, namely, pressurized chamber 101 which is pressurized with nitrogen gas, and water bath 102 by divider plate 100 as already described. The reaction process is directly observed through observation window 275 (also defining the enclosure) secured to the divider plate 100 and plate 273. The lower end of reaction tube 2 having flange 276 is supported by bracket member 277 which is secured to yoke 273 by screws 278. The reaction tube 2 is sealed to the bottom plate 273 and the bracket member 277 by O-rings 279.

Pipe 109 is connected to the hole 290 provided at the end of reaction tube 2 by means of fixture 280 secured to member 277. Support bracket 281 which is secured to plate 100 by screws 282 and has opening 283 from which cleaning solution may be flushed supports reaction tube 2. Pipes 284 and 285 held by fixtures 287 and 288 are extended onto reaction tube 2 and supply liquid sample and reagent to it. The end of pipes 284 and 285 are cut at a slant. Stirrer is rotated by a motor (not shown) which drives belt 289 in order to improve the homogeneity of the reaction solution and the reproducibility of the reaction.

All of the required operation, from the supplying of samples to the recording of data may be carried out through the operation control tape. Connected on-line with a computer this apparatus may provide digital readout valves from both the specified format and the analog indication form.

Having thus described the invention with detail and particularity as required by the Patent Laws what is desired protected by Letters Patent is set forth in the following claims:

1. An apparatus for automatically analyzing a plurality of liquid samples comprising:

a. a turntable in which sample container tubes are accomodated and means for intermittently rotating the turntable;

9 b. a reaction bath composed of a lower chamber associated with means to maintain it at a constant temperature and an upper chamber associated with means to pressurize it with inert gas;

washed into the reaction tube; and,

10 j. means for supplying at least two kinds of cleaning solutions to the cleaning means. 3. A device for cleaning the sampling system of an automatic analyzing apparatus, comprising:

c. a plurality of reaction tubes installed in the said rea. a sampler for picking up samples to be analyzed araction bath vertically positioned in both the upper ranged to move back and forth between a sample and lower chambers and opening into said upper tube containing sample and a cleaning bath; chamber; b. a means for measuring the volume of a sample d. means for drawing samples to be analyzed from picked up by said sampler;

said sample tubes rotated thereunder by the turntac. a constant flow pump connected to the said meable; suring means whereby sample is drawn from the e. means for delivering the sample to said reaction sample tube; and,

tubes; d. a means for supplying cleaning solution to the said f. means for supplying reagents to said reaction tubes sample measuring means and said sampler, the by pressurizing the said reagents with inert gas; cleaning solution passing through the said sample g. means for delivering the contents of the reaction measuring means and the said sampler being fed to tube through an opening in the bottom of the reacsaid cleaning bath. tion tube to an analytical instrument for detecting; 4. A reaction device for an automatic analyzing appaand, ratus comprising a sampler, a reagent supply device, a

b. means for cleaning the reaction tubes and said anacleaning device and an analyzer, said reaction device lytical instrument and the instrument delivering comprising: means with at least one kind of cleaning solution, a. a reaction bath composed of a lower chamber and such that all the flow lines comprising the drawing upper chamber pressurized with inert gas; means, reagent supply means, sample delivery b. a plurality of reaction tubes installed in the said remeans, and cleaning means, are isolated from the action bath within both the upper and lower chamatmosphere and pressurized with inert gas at a conbers, the top of each reaction tube opening into the stant pressure to prevent the oxidation of solutions, upper chamber and the lower end of each reaction formation of air bubbles, or the rise of noxious tube being in communication through valves with fumes. the analyzer;

2. An apparatus for automatically analyzing a pluralc. a means for providing the said lower chamber with ity of liquid samples comprising: a constant temperature circulating fluid;

a. a turntable in which sample containing tubes are d. a means for supplying sample to be treated and reaccomodated and means for intermittently rotating agents to the said reaction tube; and, the turntable; e. a means including said valves for backwashing b. a reaction bath composed of a lower chamber concleaning solution into the said reaction tubes such trolled at a constant temperature and an upper that a part of the cleaning solution is flushed into chamber pressurized with inert gas; the upper chamber of reaction bath and drained c. a plurality of reaction tubes vertically positioned in therefrom.

said reaction bath and opening into said upper 5. An apparatus according to claim I in which a bufpressurized chamber; fer tube is connected to the analyzer exhaust for cound. a means for drawing up sample to be analyzed teracting the flow through pressure of the sample so as from the said sample tubes as they are rotated to position it directly in the detector and a drain valve thereunder by the turntable; connected to said buffer tube for draining the sample e. means for measuring the volume of the sample after the sample has been analyzed by said analyzer.

drawn and delivering the sample to the reaction 6. A reaction device according to claim 4 in which a tubes; drainage device for the uppper chamber comprises:

f. a plurality of reagent selector valves each having a a. a drainage reservoir which is closed from the air,

plurality of inlets in communication with reagent and is pressurized with inert gas; reservoirs and an outlet; b. a pipe which connects the said upper chamber of g. a plurality of reaction tube selector valves conthe reaction bath and the drainage reservoir nected to said outlet of one reagent selector valve, whereby backwashed cleaning solution in the reaceach of said reaction tube selector valves selection bath may be fed to the said drainage reservoir tively applying reagent to the said reaction tubes; through the said pipe;

h. means for delivering the contents of the reaction c. an exhaust pipe for draining off the drains from tube through an opening in the bottom of the reacsaid drainage reservoirs; tion tube to an analytical instrument for detecting; d. a drainage valve connected to the said exhaust and, pipe;

i. a cleaning means comprising a plurality of valves e. level gauges for detecting the upper and lower leveach of which is connected to one reaction tube els of the drainage in the said drainage reservoir; and an analytical instrument, said valves having and, passageways for backwashing at least two kinds of f. a level detector which operates so as to open and cleaning solutions to the reaction tube and supplyclose the said drainage valve after receiving the siging said solutions to the analytical instrument and nal corresponding to upper and lower levels of the instrument delivering means and said valves having said drainage in the said drainage reservoir from outlets for draining the cleaning solutions backsaid level gauges. 

1. AN APPARATUS FOR AUTOMATICALLY ANALYZING A PLURALITY OF LIQUID SAMPLES COMPRISING: A. A TURNTABLE IN WHICH SAMPLE CONTAINER TUBES ARE ACCOMODATED AND MEANS FOR INTERMITTENTLY ROTATING THE TURNTABLE; B. A REACTION BATH COMPOSED OF A LOWER CHAMBER ASSOCIATED WITH MEANS TO MAINTAIN IT AT A CONSTANT TEMPERATURE AND AN UPPER CHAMBER ASSOCIATED WITH MEANS TO PRESSURIZE IT WITH INERT GAS; C. A PLURALITY OF REACTION TUBES INSTALLED IN THE SAID REACTION BATH VERTICALLY POSITIONED IN BOTH THE UPPER AND LOWER CHAMBERS AND OPENING INTO SAID UPPER CHAMBER; D. MEANS FOR DRAWING SAMPLES TO BE ANALYZED FROM SAID SAMPLE TUBES ROTATED THEREUNDER BY THE TURNTABLE; E. MEANS FOR DELIVERING THE SAMPLE TO SAID REACTION TUBES; F. MEANS FOR SUPPLYING REAGENTS TO SAID REACTION TUBES BY PRESSURIZING THE SAID REAGENTS WITH INERT GAS; G. MEANS FOR DELIVERING THE CONTENTS OF THE REACTION TUBE THROUGH AN OPENING IN THE BOTTOM OF THE REACTION TUBE TO AN ANALYTICAL INSTRUMENT FOR DETECTING; AND, H, MEANS FOR CLEANING THE REACTION TUBES AND SAID ANALYTICAL INSTRUMENT AND THE INSTRUMENT DELIVERING MEANS WITH AT LEAST ONE KIND OF CLEANING SOLUTION, SUCH THAT ALL THE FLOW LINES COMPRISING THE DRAWING MEANS, REAGENT SUPPLY MEANS, SAMPLE DELIVERY MEANS, AND CLEANING MEANS, ARE ISOLATED FROM THE ATMOSPHERE AND PRESSURIZED WITH INERT GAS AT A CONSTANT PRESSURE TO PREVENT THE OXIDATION OF SOLUTIONS, FORMATION OF AIR BUBBLES, OR THE RISE OF NOXIOUS FUMES.
 2. An apparatus for automatically analyzing a plurality of liquid samples comprising: a. a turntable in which sample containing tubes are accomodated and means for intermittently rotating the turntable; b. a reaction bath composed of a lower chamber controlled at a constant temperature and an upper chamber pressurized with inert gas; c. a plurality of reaction tubes vertically positioned in said reaction bath and opening into said upper pressurized chamber; d. a means for drawing up sample to be analyzed from the said sample tubes as they are rotated thereunder by the turntable; e. means for measuring the volume of the sample drawn and delivering the sample to the reaction tubes; f. a plurality of reagent selector valves each having a plurality of inlets in communication with reagent reservoirs and an outlet; g. a plurality of reaction tube selector valves connected to said outlet of one reagent selector valve, each of said reaction tube selector valves selectively applying reagent to the said reaction tubes; h. means for delivering the contents of the reaction tube through an opening in the bottom of the reaction tube to an analytical instrument for detecting; and, i. a cleaning means comprising a plurality of valves each of which is connected to one reaction tube and an analytical instrument, said valves having passageways for backwashing at least two kinds of cleaning solutions to the reaction tube and supplying said solutions to the analytical instrument and instrument delivering means and said valves having outlets for draining the cleaning solutions backwashed into the reaction tube; and, j. means for supplying at least two kinds of cleaning solutions to the cleaning means.
 3. A device for cleaning the sampling system of an automatic analyzing apparatus, comprising: a. a sampler for picking up samples to be analyzed arranged to move back and forth between a sample tube containing sample and a cleaning bath; b. a means for measuring the volume of a sample picked up by said sampler; c. a constant flow pump connected to the said measuring means whereby sample is drawn from the sample tube; and, d. a means for supplying cleaning solution to the said sample measuring means and said sampler, the cleaning solution passing through the said sample measuring means and the said sampler being fed to said cleaning bath.
 4. A reaction device for an automatic analyzing apparatus comprising a sampler, a reagent supply device, a cleaning device and an analyzer, said reaction device comprising: a. a reaction bath composed of a lower chamber and upper chamber pressurized with inert gas; b. a plurality of reaction tubes installed in the said reaction bath within both the upper and lower chambers, the top of each reaction tube opening into the upper chamber and the lower end of each reaction tube being in communication through valves with the analyzer; c. a means for providing the said lower chamber with a constant temperature circulating fluid; d. a means for supplying sample to be treated and reagents to the said reaction tube; and, e. a means including said valves for backwashing cleaning solution into the said reaction tubes such that a part of the cleaning solution is flushed into the upper chamber of reaction bath and drained therefrom.
 5. An apparatus according to claim 1 in which a buffer tube is connected to the analyzer exhaust for counteracting the flow through pressure of the sample so as to position it directly in the detector and a drain valve connected to said buffer tube for draining the sample after the sample has been analyzed by said analyzer.
 6. A reaction device according to claim 4 in which a drainage device for the uppper chamber comprises: a. a drainage reservoir which is closed from the air, and is pressurized with inert gas; b. a pipe which connects the said upper chamber of the reaction bath and the drainage reservoir whereby backwashed cleaning solution in the reaction bath may be fed to the said drainage reservoir through the said pipe; c. an exhaust pipe for draining off the drains from said drainage reservoirs; d. a drainage valve connected to the said exhaust pipe; e. level gauges for detecting the upper and lower levels of the drainage in the said drainage reservoir; and, f. a level detector which operates so as to open and close the said drainage valve after receiving the signal corresponding to upper and lower levels of the said drainage in the said drainage reservoir from said level gauges. 